Apparatus for the manufacture of dunnage bag liners

ABSTRACT

Apparatus for the manufacture of inflatable liners for disposable dunnage bags. The apparatus includes means for measuring and severing an indefinite length of flattened tubular plastic material into predetermined lengths, sealing the overlying layers at one end of each severed length, and cutting an opening in one of the layers suitable for receiving an inflation valve.

[ Nov. 25, 1975 United States Patent 1191 Hollis 1 APPARATUS FOR THEMANUFACTURE OF 3,352,737 11/1967 93/8 VB x DUNNAGE BAG LINERS 3.355.99612/1967 Medleycott et al..

93/8 VB X Lotto1.........................,

3,646,856 3/1972 Worndl................ 3,813,998 6/1974 93/DIG. l X

[75] Inventor: Clinton R. Hollis, Camden, Ark.

7 Primary Examiner-Roy Lake [73] Assignee: International Paper Company,New

York, N.Y.

Assistant Examiner-James F. Coan [22] Filed: Mar. 4, 1974 Attorney,Agent, or FirmFitch, Even, Tabin & Luedeka 21 Appl. No.2 447,763

[57] ABSTRACT Apparatus for the manufacture of inflatable liners for[52] US. 93/8 VB; 93/1 WZ; 93/33 H;

O M n 3 31 mRL 300V B .983 4V man 1 ,5 B 1 1 m mined lengths,'sealingthe overlying layers at one end References Cited UNITED STATES PATENTSof each severed length, and cutting an opening in one of the layerssuitable for receiving an inflation valve.

3,069,303 12 1962 SChOll6...........i. 93/010. 1 3,244,576 4/1966 93/8VB x Clams 27 Drawing Flgures US. Patent Nov.25, 1975 Sheet1of73,921,506

US. Patent N0v.25, 1975 Sheet20f7 3,921,506

Fig. 20

Fig. 2.

US. Patent N0v.25, 1975 Sheet30f7 3,921,506

US. Patent N0v.25, 1975 Sheet4of7 3,921,506

Ila";-

US. Patent N0v.25, 1975 Sheet60f7 3,921,506

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hn E APPARATUS FOR THE MANUFACTURE OF DUNNAGE BAG LINERS This inventionrelates to apparatus for the manufacture of inflatable liners fordisposable dunnage bags.

Dunnage bags have been used heretofore to fill the unoccupied space inan incompletely filled truck or rail car, thereby preventing shifting ofthe partial load during transit. Because the size of such unoccupiedspace is not predeterminable prior to loading the vehicle, inflatabledunnage bags have been used as a means to fully occupy whatever spacewithin the vehicle is vacant. Preferably, the dunnage bags are notreused inasmuch as they are prone to develop tears, rips or other pointsof weakness which pose potential rupture points during subsequent reuseand resultant loss of control over the load. Because the bags areintended to be used only once and thereafter disposed of, it isdesirable that the cost of the bags be kept low.

One dunnage bag of the prior art comprises a multilayered kraft outerbag fitted with an inflatable liner or bladder disposed inside the kraftbag. To keep the cost of the dunnage bag low, the inflatable linerpreferably is made from a thin-wall plastic, such as polyethylene havinga wall thickness of about 4 to 6 mils. This sheet material is readilyavailable in rolls of flattened tubing of indefinite length. Such flatsheet material comprises two flat layers overlying each other and joinedto each other along their mutual side edges. When cut to suitablelengths, fitted with an inflation valve, and sealed at its ends, thismaterial makes suitable liners for dunnage bags.

In the manufacture of a plastic liner for a dunnage bag, the thin wallof the plastic and its low friction coefficient makes it difficult tohandle or manipulate, particularly when in flat sheet form. Oneparticular problem is the tendency of the thin plastic sheet to wrinklewhen it is attempted to move the sheet through an apparatus in a flatcondition.

Further, in manufacturing dunnage bags having plas' tic liners, it hasbeen found important to maintain the dimensions of the linersubstantially identical to the inside dimensions of the kraft bag sothat the liner fits snugly inside the kraft bag without wrinkles. When aliner is inflated, any wrinkles develop potential rupture points whichcould result in catastrophic failure of the bag during transit andresultant disastrous shifting of the load. Further, it is important thatthe inflation valve fitted in the liner be positioned precisely so thatwhen the liner is inserted in the outer kraft bag, the valve willregister with an opening in the wall of the kraft bag and the inflationvalve will be exposed externally of the bag to permit subsequentinflation.

It is therefore an object of this invention to provide apparatus for themanufacture of an inflatable liner for a dunnage bag. It is anotherobject of this invention to provide an apparatus for the manufacture ofa dunnage bag liner which is flat, rectangular, of precise length andwidth dimensions, and for providing a precisely located opening in onewall of the liner for receipt of an inflation valve.

Other objects and advantages will be apparent from the followingdescription, including the drawings, in which:

FIG. 1 is a representation of apparatus including vari- OI 'eatures ofthe invention;

LII

FIG. la is a representation of a product produced by the apparatus ofFIG. 1;

FIG. 2 is an elevation view of the left side of the apparatus dipictedin FIG. 1;

FIG. 2a is a fragmentary representation of a sheet material movementmonitoring device;

FIG. 3 is a fragmentary sectional view, partly schematic, of sealing andcutting portions of the disclosed apparatus, including the drive rolls;

FIG. 4 is a fragmentary sectional view of a portion of the forward endof the apparatus depicted in FIG. 1;

FIG. 5 is a fragmentary view of the cutting end of a rotary knife;

FIGS. 6 and 7 are side elevation and plan views, respectively, of oneembodiment of a hole cutter device as disclosed herein;

FIG. 8 and 9 are a side elevation view, with one side plate removed, anda plan view, respectively, of a cutoff knife device as disclosed herein;

FIG. 10 is an end elevation view of the left end of the device depictedin FIG. 8;

FIGS. 11, 12 and 13 are side elevation, plan, and end views,respectively, of a block for holding a cutoff knife;

FIGS. 14 and 15 are side and top views, respectively, of a cutoff knife;

FIG. 16 is a representation of a rotary valve employed with the holecutter depicted in FIG. 6;

FIGS. 17, 17a, 18, 18a, 19, 19a, 20, and 21 depict a rotary valveemployed in controlling the functioning of the cutoff knife depicted inFIGS. 8 and 9; and,

FIG. 22 is a schematic representation of a control system, showingpneumatic and electrical features, for the apparatus depicted in FIG. 1.

The disclosed apparatus includes means for storing and dispensing asupply of flattened tubular sheet material, means for feeding the sheetmaterial in a flat condition forwardly from the storage means, means formonitoring the forward movement of the sheet and stopping such forwardmovement at predetermined intervals, means for severing the sheetmaterial across its width when it is stopped, means for sealing one endof each severed section of tubular sheet material, and means for cuttingan opening through one of the layers of the sheet material at a locationadjacent the unsealed end of each severed section.

In the depicted embodiment, the apparatus includes frame means 10 havingforward and rear ends 12 and 14 respectively. The sides of the frameinclude base members 16 and 18, vertical members 20, 22, 24, 26, 28 and30. The opposite sides of the frame are joined to each other as byhorizontal cross members 32, 34 and 36.

A pair of upright standards 38 and 40 are mounted on opposite sides ofthe rear end 14 of the frame base members 16 and 18. The top end 42 ofeach standard is provided with a slot 44 defining a support for thespindle shaft 46 of a supply roll 48 of flattened tubular sheet material50 disposed in a horizontal position and extending across the width ofthe frame in position to be passed through the apparatus.

A dancer roll 52, journaled at its opposite ends 54 and 56 in theoutboard ends 58 and 60 of a pair of arms 62 and 64 which are hingedlyconnected to the horizontal frame members 28 and 30, extends across thewidth of the frame 10. In this manner the dancer roll 52 is free to movein a generally arcuate path about the hinge axis of the arms 62 and 64and, by virtue of its 3 weight, to maintain a downward pressure againstthe sheet material 50 when such sheet material is wrapped about thedancer roll as appears more fully hereinafter.

Above the dancer roll and rearwardly thereof there is provided an idlerroll 66 including a shaft 67 rotatably mounted at its opposite ends 68and 70 to the horizontal frame members 28 and 30 so that it extendsacross the width of the frame.

Above and forwardly of the idler roll 66, there is provided a brakingmeans comprising a brake roll 74 whose opposite ends are journaled inupright standards 76 anad 78 that are secured to the horizontal framemembers 28 and 30, respectively. The braking means further includes anelongated brake beam 72 which also extends across the width of the frameand substantially parallel to the brake roll 74. This beam 72 includes aflat face 80 disposed above and, in juxtaposition to the brake roll 74,the face 80 having mounted thereon a strip of friction material 82facing the brake roll 74. The opposite ends 84 and 86 of the beam 72 aresecured to the ends 88 and 90, respectively, of rocker arms 92 and 94pivotally mounted by shafts 95 and 98 to the upright standards 76 and78. As thus mounted, the beam 72, hence the friction strip 82, ismovable toward and away from the brake roll 74 upon movement of therocker arms 92 and 94.

A set of drive rolls is mounted on the frame at a location forwardly ofthe brake means, each of the rollers of the set being disposedhorizontally across the frame. This set of drive rolls includes afriction drive roll 96 having a shaft 97 extending from opposite endsthereof and journaled at one end 99 in one end 100 of the rocker arm 92.The shaft 97 is further journaled at its opposite end in the end 102 ofthe rocker arm 94 so that the friction drive roll 96 is translatablealong a generally vertical path in response to rocking movement of therocker arms 92 and 94. The end 99 of the shaft 97 is further providedwith a spur gear 104 fixedly mounted thereon.

The set of drive rolls further includes a smooth surface drive roll 106having a shaft 108 extending from the opposite ends thereof, such rollbeing oriented substantially parallel to the friction drive roll 96 andin juxtaposition thereto to define a nip 110 therebetween. One end ofthe shaft 108 is journaled in the upright standard 76, with the oppositeend of the shaft 108 being journaled in the upright standard 78 disposedon the opposite side of the frame. The end of the shaft 108 extendslaterally beyond its journaled mounting in the standard 78 and isprovided with a spur gear 114 fixedly secured thereon. This gear 114 onshaft 108 is substantially identical in size to the gear 104 on theshaft 97 and meshes therewith so that the shafts turn simultaneously andin opposite direction when the gears 114 and 104 are rotated. Theopposite end of the shaft 108 is provided with a further spur gear 116which is drivingly connected by a drive chain 118 to a gear 120 on theoutput shaft (not visible) of a gear reducer 122 connected to a motor124 such that operation of the motor functions to rotate the frictiondrive roll and the smooth surface drive roll in unison. In the preferredembodiment, the motor 124 operates continuously while the apparatus isfunctioning thereby continuously rotating the drive rolls. The limit ofrocking movement of the rocker arms 92 and 94 which raises the frictiondrive roll 96 away from the drive roll 106 is less than that which willallow the gears l 14 and 104 to move out of driving engagementtherebetween so that 4 when the friction drive roll 96 is raised, itcontinues to rotate.

Preferably the friction drive roll 96 is provided with a plurality ofresilient circumferential friction rings 126 spaced apart substantiallyequal distances from each other along the length of the friction driveroll 96. As depicted, each of the rings 126 preferably resides in acircumferential groove in the circumference of the roll 96 to aid inmaintaining the relative spacing between the rings. The circumference ofthe friction roll 96 is chosen to be less than the circumference of thedrive roll 106 by an amount such that when the rolls frictionally engagethe sheet material between them and the resilient rings 126 arecompressed, the circumference of the rings, as compressed, substantiallyequals the circumference of the drive roll 106 thereby providing forsubstantially equal tangential speeds of those surfaces of these tworolls that engage the sheet material. In this manner, the driving forcesimparted to the top and bottom layers of the flattened tubular sheetmaterial are substantially equal and the sheets are moved forwardlysimultaneously. This structure and the use of multiple spaced apartfriction rings has been found effective in preventing wrinkles in thebilayered sheet material when driving it forwardly through theapparatus. Further, the friction rings function to align the lengthdimension of the sheet material with the desired forward direction oftravel through the apparatus.

Movement of the brake beam 72 and the friction drive roll 96 betweentheir respective positions of engagement and disengagement with thesheet material fed through the apparatus is effected simultaneously bymounting these two elements on opposite ends of the rocker arms 92 and94. It is noted that when the brake beam is in its position ofengagement, the friction drive roll is in its position of disengagementand vice versa. To effect movement of the rocker arms, the shaft of therocker arm 92 has fixedly secured thereto an elongated arm 128 thatextends rearwardly from the shaft 95 and along the side of the frame 10.The rear end 130 of the arm 128 is upturned and provided with an openingthrough which there is slidably received a rod 132. A set screw 134 isprovided to secure the rod 132 in a chosen position within the opening.The rear end of the rod 132 is pivotally connected to a clevis 136mounted on the end of a piston 138 of a piston-cylinder 140 that ismounted on a plate 142 which is slidably received on a rail 144 whoseopposite ends are mounted in blocks 146 and 148 secured to the framemember 28. In this manner, the relative positions of the piston-cylinder140, the rod 132 and the arm 128, are adjustable to select the distancebetween the shaft 95 and the piston 138 and thereby set the limits ofrotation of the shaft 95 by vertical movement of the piston 138, henceset the limits of the rocking movements of the rocker arms 92 and 94 toestablish the desired positions of the brake beam 72 and the frictiondrive roll 96 relative to the brake roll 74 and the drive roll 106,respectively. The depicted piston-cylinder 140 is single acting with itspiston 138 spring-biased toward its retracted position. Admission ofpneumatic pressure to the piston-cylinder 140 and exhausting the same iseffected by a solenoid valve 150 interposed between the piston-cylinder140 and a source of pneumataic pressure (See FIG. 22).

A generally planar apron 152 is disposed across the frame in a generallyhorizontal plane with its leading edge 154 disposed adjacent the nip 110between the drive rolls 96 and 106. The apron 152 extends from the nipof the drive rolls forwardly to define a flat smooth surface 156.Preferably the leading edge 154 of the apron is inclineddownwardly toguide the sheet material from the nip llOonto the top surface 156 of theapron.

in the depicted embodiment the apron 152 is mounted on a slide beam 160comprising an inverted U beam having depending longitudinal sides 162and 164 extending along its length. One of the sides 162 is mounted inthe circumferential groove of a pulley 166 that is rotatably mounted onthe end of a shaft 165 mounted in the frame cross member 36. The otherlongitudinal depending side 164 of the beam 160 is slidably received ona rail 163 disposed on the upper surface 168 of the frame cross member36, thereby slidably mounting the beam for movement in a directiontransverse to the frame length.

Adjacent one end 180 of the beam 160 there is provided an openning 182extending through the thickness of the beam and the overlying apron todefine a vacuum port for the application of suction to the upper surface170 of the apron. Further, on the end 180 of the beam 160 there ismounted a hole cutter 184 adapted to cut a circular opening in the toplayer of the bilayered sheet material. As depicted in FIGS. 3, 6 and 7,the hole cutter 184 comprises a cutting head 186 including a hollowtubular knife 188, having one of its ends sharpened to define a circularcutting edge 190, rotatably mounted in a housing 192 as by means ofbearings 194 and-196. The end of the knife 188 opposite the cutting endis provided with a sheave 198 fixed thereto and drivingly connected by abelt 200 to a sheave 202 fixed on the shaft 204 of a motor 206. When theapparatus is in operation, the motor 206 runs continuously so that thecutting knife is rotating at all times.

The housing 192 holding the knife 188 is pivotally mounted on a shaftwhich forms a rotating member 208 of a rotary valve 210. The shaft isrotatably mounted at its opposite ends in a pair of blocks 212 and 214that are secured to the top 170 of the beam 160. In this manner thehousing 192 is adapted to be moved such that the cutting head 186 movesalong the arcuate path toward and away from the sheet material disposedon the top of the apron 152. One of the blocks 214 defines a stationarymember of the rotary valve 210. This stationary member is provided withtwo inlets 216 and 218, one of which is connected by a conduit 220 to avacuum pump 222 and the other of which is connected by a conduit 224 toa source of pneumatic pressure. The rotating member 208 of the rotaryvalve 210 is provided with an outlet 226 which is connected by means ofa conduit 228 to the top end of the hollow knife 188 and to the bottomvacuum port 182 so that suction applied through the outlet 216 exertsits influence at the cutting edge of the rotary knife and at the bottom:vacuum port. A check valve 230 isinterposed in the conduit 228 toprevent the passage of pressurized air to the bottom vacuum port 182.v a

The rotary member 208 of the rotary valve 210 is provided with openings232 nd 234 therethrough at cations such that when the cutting knife islowered to a position adjacent the sheet material, theopening 232 in therotating member is aligned with the vacuum inlet 216 of the stationarymember of the rotary valve thereby applyingv suction through the rotaryvalve and conduit 228 to the top and bottom layers of the sheetmaterial. Upon movement of the cutting head away from the sheetmaterial, the opening 232 in the rotating member 208 moves out ofregister with the vacuum inlet 216 thereby cutting off the vacuum andreleasing the sheet material. As the cutting head 186 is furtherrotated, the opening 234 in the rotating member 208 comes into registerwith the pressure inlet 218 of the stationary member to admitpressurized air to the top end of the rotary knife 188 to blow thecircular plug cut from the sheet material out of the rotary knife.Further upward movement of the cutting head moves the opening 234 out ofregister with the pressure inlet 218 to halt the flow of pressurized airthrough the rotary knife.

The housing 192 is further connected by a clevis 251 to the end of apiston 252 of a piston-cylinder 254, the latter being mounted on anupstanding plate 256 secured to the side 162 of the beam so that thehole cutter 184 is movable with the beam 160 in a direction transverseto the direction of forward movement of the sheet material through theapparatus. This freedon of movement of the hole cutter provides lateraladjustment of the cutting head relative to the edge 258 of the sheetmaterial moving through the apparatus so that the location of the holecut in the top layer of the sheet material will be located an exactdistance inwardly of the sheet material from its edge 258. Lateralfreedom of movement of the hole cutter is made necessary by reason ofthe uneveness commonly found in the edges of a wound roll of sheetmaterial. Being movable, the hole cutter may be moved in and out tofollow the variable position of the edge 258 of the sheet material asthe sheet material is moved through the apparatus. Such movement of thehole cutter may be effected manually or, if desired, provision may bemade for automatically sensing the position of the edge of the sheetmaterial and developing a signal to drive the beam 160, hence the holecutter 184, in and out as required to fol:

lnw the edge. 258.

The cylinder 260 of the piston-cylinder 254 is connected through asolenoid valve 262 to a source of pneumatic pressure. Upon opening ofthe solenoid valve 262, and resultant extension of the piston 252 thehousing 192 is pivoted to lower the cutting head 186 to a positionimmediately above the sheet material. Upon closing of the valve 262.,the piston moves to its spring-biased retracted position to raise thecutting head 186 away from the sheet material.

Downstream from the hole cutter means there is provided a heat sealingmeans 263 extending across the frame 10 comprising a horizontal supportbeam 272 mounted at its opposite ends on the frame 10 by means ofupright standards 274 and 276. An elongated heat seal bar 278, having alength at least equal to the width of the sheet material beingprocessed, is connected to the beam 272 by means of a pair ofdouble-acting piston-cylinders 280 and 282 which depend from the beam272. The piston members 284 anad 286 of the piston-cylinder units 280and 282 are connected to the heat seal bar 278 at separated locations sothat extension and retraction of the pistons 284 and 286 serves to lowerand raise the heat bar relative to an elongated anvil member 289disposed in top surface 290 of a bar 292 disposed across the frame 10beneath the seal bar 278. The seal bar 278 is of relatively narrow widthand heated by means of a heater 295 inserted in the bottom edge 294 ofthe bar and extending along its length to provide substantially uniformheating of the bottom edge 294 of the bar. Electrical power foroperating the heater 295 is fed from a source 297 of such power througha thermostat 299 to the heater.

The bar 278 is flanked on its opposite sides by clamp members 296 and298, one of which is spring mounted on each of the opposite sides of theheat seal bar as by bolts 300 threadably received in the top surface 302of each clamp member 296 and extending upwardly therefrom to be slidablyreceived in a ledge 304 extending horizontally from the side of the heatseal bar. Each of the clamps 296 and 298 is of substantially the samelength as the heat seal bar 278 and extends substantially paralleltherewith across the frame -10. Spring means 306 is provided on each ofthe bolts 300 such that when the several springs are relaxed, the clamps296 and 298 depend below the vertical level of the bottom edge 294 ofthe bar 278. Upon movement of the bar into contact with the anvil member289 disposed below the bar, the clamps are moved into alignment with thebottom of the seal bar, thereby expanding the springs 306 and biasingthe clamps against the top surfaces of the bar 292 and the channel 340.

A first switch means 320 is mounted on the upright standard 276 at alocation above and adjacent one end 322 of the heat seal bar 278. Afirst contact arm 324 mounted on the end of the heat seal bar engages aswitch arm 326 of the first switch means 320 upon movement of the heatseal bar to its upper position. A second switch means 328 is mounted onthe upright standard 274 at a location above and adjacent the oppositeend 330 of the heat seal bar 278. A third switch means 332 is alsomounted on the upright standard 274 at a location above the heat sealbar, but below the second switch means 328. Each of the second and thirdswitch means includes a switch arm 334 and 336, respectively. A contactarm 338 on the end 330 of the heat seal bar 278 is provided to engagethe switch arm 336 of the third switch means 332 when the heat seal baris in its lower position.

A cutoff knife 340 for severing the sheet material across its width ismounted on the frame 10 at a 1ocation adjacent to and rearwardly of theheat seal bar 278. This cutoff knife comprises a double edges blade 342secured to a slide block 344 which is slidably contained in a tubularchannel 346 that extends across the frame 10 at a location rearwardly ofthe heat seal bar. The channel 346 is provided with a slot opening 348through which the cutting edges 350 and 351 of the blade project topresent the double cutting edge at a vertical level above the top 352 ofthe channel 346. As seen in FIG. 3, the slot 348 is located rearwardlyof the seal bar 278 and forwardly of the clamp 298 so that when the sealbar and its clamps are lowered into engagement with the sheet material,the sheet material is secured held for the knife to make a cut acrossthe width of the sheet material. Notably, this cut is made immediatelyrearwardly of the seal made by the seal bar 278 so that the forward cutedge of the sheet material defines one end 502 of the liner 500.

The slide block 344, hence the blade 342, is moved along the length ofthe channel 346 preferably by pneumatic pressure. To this end, thechannel 346 has connected to the opposite ends thereof conduits 354 an356 that lead through a rotary valve 358 to a source 360 of pneumaticpressure. The block 344 is preferably of light weight construction,hence has substantial portions thereof cut away. In the preferredembodiment, each end of the block is provided with a closed bore 362adapted to receive therein a hollow tubular piston member 364 mounted atthe end of the channel 346 in horizontal alignment with the axis of thebore 362. It

will be recognized that when the block 344 moves into engagement withthe piston 364, as shown by the dotted line position of the block 344 inFIG. 8, air is trapped in the annular space 363 between the outer wallof the piston 364 and the inner wall of the channel 346 and compressedto exert a braking effect upon the moving block. Preferably the pistonmember 366 is provided with an O-ring 366 encircling the piston adjacentits outboard end to insure adequate entrapment of air within the annularspace 363. The opposite end 368 of the channel 346 is provided with alike piston member 370 which functions to brake the block when it ismoved in a direction toward the end 368 of the channel.

As visualized from FIG. 8, when the hollow piston 364 resides in thebore 362 of the block 344, pneumatic pressure admitted through theconduit 354 is initially captured in the bore 362 and effective againstthe bottom of the bore to impart a force against the block sufficient topropel it rapidly along the length of the channel 346.

Referring to FIGS. 21 and 22, the rotary valve 358 which controls theadmission of pneumatic pressure to the ends of the channel 346 isconnected by means of a conduit 372 to a source of pneumatic pressure360. The depicted rotary valve comprises an inlet member 374 having aninternal bore 376 divided at one end of the member into two legs 378 and380 which open inwardly of the valve. A central rotating member 382 isdisposed between the inlet member 374 and a station- 1 ary outlet member384 of the rotary valve. This central rotating member is adapted to berotated about its axis by means of a pawl 386 attached to the piston 388of a piston cylinder 390 whose actuation is controlled by a solenoidvalve 392. The pawl 386 engages cross rods 394 on the central rotatingmember 382 when the pawl is extended by the piston 388. By design, eachfull extension of the piston 388 results in rotation of the rotarymember 382 by one-quarter turn.

The valve 392 controlling the piston-cylinder 390 is connected by lead322 to the switch 332 so that the electrical signal developed by thisswitch when the seal bar 278 is lowered causes the valve 392 to open andadmit pneumatic pressure to the piston-cylinder 390, extend the pawl 386and rotate the central rotating member 382 of the rotary valve. Further,when the seal bar 278 is raised, the signal from the switch 332 causesthe valve 392 to close, exhaust the pneumatic pressure and allow thepiston 388 to retract the pawl 386 under the influence of a spring biasprovided in the piston-cylinder 390.

The stationary outlet member 384 of the rotary valve 358 is providedwith openings 396 and 398 which register with openings 400 and 402leading through the central rotary member 382 in preselected sequence,depending upon the rotational position of the central rotary member 382,alternately admitting pressurized air from the inlet member 374, throughthe central rotary member 382 to one of the outlets 396 and 3980f theoutlet member 384. The outlet 396 of the valve outlet member 384 isconnected by conduit 354 to one end 406 of the channel 346. The other ofthe outlets 398 is connected by a conduit 356 to the opposite end 412 ofthe channel 346 so that pressurized air for propelling the knife block344 along the channel 346 is admitted first to one end of the channel topropel the knife along the length of the channel and perform a cut ofthe sheet material across its width, and thereafter is admitted to 9 theother end of the channel to reverse the direction of travel of the knifeand thereby effect a cut of the sheet maerial in such reverse direction.By this means the knife is made to cut in both of its directions oftravel.

The cutting blade 342 preferably is formed of relatively thin metalhaving a substantial spring constant. The depicted blade issubstantially rectangular except that one long side has double taperededges 350 and 351, each of which is sharpened to define a cutting edge,so that the blade is capable of cutting when moved in either directionacross the width of the frame 10. To mount the blade in the block 344,the block is provided with two parallel vertical slots 420 and 422 onone side of the block. These slots are spaced apart by a distanceslightly less than the length of the blade 342.

The blade is attached to the block by bending the blade, inserting itsopposite ends 424 and 426 in the slots 420 and 422 and releasing thebending moment of the blade so that the blade springs back to holditself in the slot.

FIGS. 2 and 2a depict a means for monitoring the lineal movement of thesheet material through the depicted apparatus and includes a meteringwheel 430 rotatably mounted on the end 431 of an arm 432 whose oppositeend 434 is pivotally hinged to the frame cross member 32 so that themetering wheel 430 may be moved along an arcuate path between positionsof engagement and disengagement with sheet material wrapping the brakeroll 74. The metering wheel is connected through a gear box 436 to a cam438 such that rotation of the metering wheel effects rotation of thecam. The cam 438 is provided with a notch 440 in its periphery forreceiving the switch arm 442 of an electric switch 444. Preferably thecircumference of the wheel 430 is provided with a friction rim 446 toinsure good driving contact between the wheel and the sheet material 50as it moves over the roll 74 beneath the wheel. As will appear morefully hereinafter, when the sheet material is moved forwardly throughthe apparatus, the wheel 430, by reason of its frictional engagementwith the sheet material, is caused to rotate. This rotation of the wheelis transferred through the gear box 436 to the cam 438 to rotate thecam. Because of the direct connection between the metering wheel and thecam, each rotation of the metering wheel effects a predetermined degreeof rotation of the cam with the result that through choice of the lengthof the circumference of the metering wheel, a predetermined length ofsheet material may be moved through the apparatus per each rotation ofthe cam. Each rotation of the cam brings the notch 440 into registerwith the arm 442 of the switch 444 to cause the switch to open and closein response to the rotational position of the notch.

With reference to the schematic control system depicted in FIG. 22 theswitch 328 is connected by an electrical lead 450 to the solenoid valve150, which controls the actuation of the braking and drivepistoncylinder 140, to provide an appropriate electrical signal to openthe valve 150 when the arm 334 of the switch 328 is engaged by thecontact 338 upon raising of the seal bar 278, thereby admittingpneumatic pressure to the piston-cylinder 140 to extend the piston 138and rotate the rocker arms 92 and 94 to move the brake beam 72 out ofengagement with the sheet material wrapping the brake roll 74 and,simultaneously, to move the friction drive roll 96 into engagement withthe sheet material, thus commencing forward movement of the sheetmaterial through the apparatus. The valve 150 is closed to shut off thepiston-cylinder 140 from the source of pneumatic pressure and permit thepiston 138 to return, under the influence of its spring bias, to itsretracted position, when the seal arm 278 is lowered and the contact 338disengages the arm 334 of the switch 328. This movement of the piston138 results in movement of the rocker arms 92 and 94 to move the brakebeam 72 to its engaged position and the friction drive roll 96 to itsposition of disengagement with the sheet material. Because the driverolls continuously rotate, the sheet material immediately commences itsforward movement when gripped in the nip between the drive rolls uponthe friction drive roll being moved to its position of engagement withthe sheet material.

As noted above, the pneumatic pressure source 360 is further connectedby a conduit 372, through the solenoid valve 392, to the piston-cylinder390 which functions to rotate the central rotary member 382 of therotary valve 358. This solenoid valve 392 is connected by electricallead 460 to the switch 332 so that the electrical signal developed bythis switch, when its arm 336 is contacted by reason of the seal bar 278achieving its lowered position, is fed to the valve 392 to open thevalve and admit pressurized air to the cylinder 390 and extend thepiston 388 to move the pawl 386 into contact with the central rotaryportion of the rotary valve 358 and rotate such central portiononefourth of a turn. In a preferred embodiment, the cylinder 390 isconnected to a closed container 462 of adjustable volume, therebycausing the pressure within the cylinder 390 to increase rapidlyinitially and thereafter more slowly due to the restricted exhaust ofcylinder 390, with the result that the central rotary member 392 isturned first rapidly and then slowly through its onefourth turn. Thisaction provides for rapid movement of the central member 382 at the timeof aligning one of its openings with an opening in the outlet member 384thereby maximizing the rate of pressure rise in the channel 346 behindthe block 344 to provide maximum propelling force to the block and theblade 342 carried thereon.

When the seal bar is raised the signal from the switch 332 to the valve392.0n piston-cylinder 390 is cut off causing this valve to close andexhaust the pressure from the piston-cylinder 390, thus retracting thepawl 386 to a position suitable for subsequent reengagement with therotary valve 358.

Further, the electrical signal developed by the switch 444 when its arm442 resides in the notch 440 of the cam 438 is fed by an electrical lead464 to a timer 470, which provides a signal to a solenoid valve 466 toopen this valve and admit pneumatic pressure, by conduits 463 and 465,simultaneously to the piston-cylinders 280 and 282 to lower the seal bar278 against the sheet material disposed therebelow. When the timer 470times out, it develops an electrical signal which serves to reverse thesolenoid valve 466 and direct pneumatic pressure, by conduits 471 and473, to the bottom ends 472 and 474 of piston-cylinders 280 and 282 toraise the seal bar.

When the seal bar reaches its upper position, the contact 324 on the barengages the arm 326 of the switch 320 and develops an electrical signalthat is fed to the timer 470 to reset the timer.

In an operation of the depicted apparatus, the sheet material 50 is fedforwardly and downwardly from the supply roll 48 and wrapped around thedancer roll 52, thence upwardly and rearwardly to partially wrap theidler roll 70. From the idler roll, the sheet is fed forwardly inpartially wrapping engagement with the brake roll 74, between the brakeroll and the brake beam 72. From the brake roll, the sheet material isfed forwardly through the nip 110 between the friction drive roll 96 andthe smooth surface drive roll 106, thence over the apron 152 and the topsurface of the channel 346 to pass beneath the heat seal bar.

At the start of an operation of the disclosed apparatus, the frictiondrive roll 96 is in its upper position out of engagement with the sheetmaterial, the heat seal bar 278 is in its upper position out ofengagement with the sheet material, the brake beam 72 is engaged withthe sheet material wrapping the brake roll 74, and the metering wheel430 is positioned with its rim 446 engaging the sheet material wrappedabout the brake roll. Also, the pneumatic pressure in the source 360 isestablished and the timer 470 is timed out.

Upon actuation of the apparatus by closing an appropriate switch 471,the control system of the apparatus is connected to a source ofelectrical power 297 and thereby energized, at the same time startingthe motor 124, the motor 206, and the vacuum pump 222. The motors 124and 206 and the vacuum pump 222 run continuously during the operation ofthe apparatus. Energizing the system with the seal bar 278 raised andthe contact 338 engaging the arm 334 of the switch 328 functions tosupply an electric signal appropriate to open the solenoid valve 150 toactuate the piston-cylinder 140 and move the friction drive roll 96 intoengagement with the sheet material, while simultaneously raising thebrake beam 72 and releasing the sheet material for movement through theapparatus.

As the sheet material moves through the apparatus, the metering wheel isrotated, resulting in rotation of the cam 438. After the desired lengthof sheet material has passed through the apparatus, the arm 442 of theswitch 444 falls into the notch 440 on the cam to develop an electricsignal which actuates the timer, hence the solenoid valve 466 to admitpneumatic pressure to the piston-cylinders 280 and 282 to lower the heatseal bar 278, and its flanking clamps 296 and 298, into engagement withthe sheet material disposed beneath the heat seal bar. When the heatseal bar moves downward and the contact 338 disengages the arm 334 ofthe switch 328, the valve 150 closes and deactivates the piston-cylinder140 to raise the friction drive roll out of engagement with the sheetmaterial and lower the brake beam into engagement with the sheetmaterial to stop forward movement of the sheet material through theapparatus.

As noted above, when the seal bar reaches its lowered position, thecontact 338 actuates the switch 332 to develop a signal which actuatesthe valve 392 controlling the piston-cylinder 390 that turns the centralrotating member 382 of the rotary valve 358 to admit pneumatic pressureto one end of the channel 346 to propel the cutoff knife along thelength of the channel and sever the sheet material while it is stopped.

The signal from the switch 332 further serves to open the solenoid valve262 to admit pneumatic pressure to the piston-cylinder 254 and move thecutting head 186 into position adjacent the top layer of the bilayeredsheet material disposed on the top surface 170 of the slide beam 160. Asnoted hereinbefore, as the rotary cutting head moves into positionadjacent the sheet material, it rotates the rotary valve 210 to applysuction to both the bottom and top layers of the sheet material disposedbetween the two vacuum heads. Upon the ap- 12 plication of the suction,the bottom layer of the sheet material is pulled downwardly against thetop surface 170 of the apron 152 and the top layer of the sheet materialis pulled into engagement with the rotating cutting knife 188 to causethe knife to cut a circular plug from the top layer of the sheetmaterial.

The timer 470 is set to time out after the heat seal bar has been incontact with the sheet material for a time sufficient to effect a heatseal of the top layer of the sheet material to the bottom layer. Whenthe timer times out, it provides a signal to the solenoid valve 466causing it to exhaust pneumatic pressure from the top ends of thepiston-cylinders 280 and 282 and simultaneously admit pneumatic pressureto the bottom ends of these piston-cylinders to move the heat seal barto its upper position out of engagement with the sheet material. Thismovement of the seal bar 278 disengages the contact 338 from the switch332 to cut off the signal to the solenoid valve 262, causing this valveto close the exhaust the pneumatic pressure from the piston-cylinder 254to raise the cutting head away from the sheet material. As the cuttinghead 186 is swung upwardly, it rotates the rotary valve 210 tosequentially close off the vacuum and momentarily admit pneumaticpressure through the central bore of the cutting knife 188 to expel theplug that was cut from the sheet material. The check valve 230interposed in the conduit 228 functions to prevent the flow ofpressurized air to the bottom vacuum port 182. As the cutting head isswung further upwardly, the rotary valve is turned to close off thepneumatic pressure source from the hollow knife 188.

Upon the heat seal bar 278 reaching its upper position, the contacts 324and 338 engage the arms 326 and 334 of the switches 320 and 328,respectively, to reset the timer to open the valve 150 to admitpneumatic pressure to the piston-cylinder for releasing the brake beamand moving the friction drive means to contact with the sheet materialfor commencing a further cycle of operation.

Each severed length 500 of tubular sheet material (see FIG. 1a), havingone of its ends 502 sealed and provided with an opening 504 in one ofits layers is manually removed from the apparatus to a subsequentprocessing station. As noted hereinbefore, each liner is fitted with aninflation valve. This inflation valve is put in place after the linerhas been severed by the disclosed apparatus so that it is necessary thatone end of each severed length of sheet material remain open to permitaccess to the inside of the liner for fitting the inflation valve in theliner. To this end, the disclosed apparatus provides for positioning thehole cutter 184 adjacent to the cut-off knife 340 and rearwardlytherefrom to thus position the opening 504 a proper distance to the rearof the unsealed cut end 506 of each severed length of sheet material.Similarly, the cut-off knife 340 is positioned rearwardly of the heatseal bar 278, between thehole cutter and the seal bar, to sever thesheet material across its width at a location rearwardly of and adjacentto the seal508 across the sheet material.

Liners, as depicted in FIG. 1a, are produced at a rapid rate, hence at arelatively low unit cost, employing the disclosed apparatus. By reasonof the ability of the apparatus to rapidly move the bilayered sheetmaterial through the apparatus without developing wrinkles in one orboth layers and/or without buckling the sheet material, the length ofeach liner is precisely measured and the location of the hole for theinflation valve is 13 precisely positioned. It has been found that thepercentage of liners rejected due to apparatus failure, malfunction,etc. is essentially nil.

While a preferred embodiment has been shown and described, it will beunderstood that there is no intent to limit the invention by suchdisclosure, but rather, it is intended to cover all modifications andalternate constructions falling within the spirit and scope of theinvention as defined in the appended claims.

What is claimed:

1. In an apparatus for the manufacture of an inflatable linerfor adunnage bag employing a supply of flattened tubular sheet material ofindeterminate length that exceeds its transverse dimension theimprovement comprising in combination frame means, drive roll meansadapted to move said sheet material forwardly through said apparatus ina flat condition when in engagement with said sheet material,

means adapted to rotate said drive roll means,

brake means adapted to stop movement of said sheet material through saidapparatus when in engagement with said sheet material,

rocker means connecting said drive roll means and said brake means,

means connected to said rocker means and adapted to impart a rotatingmotion to said rocker means whereby said drive roll means and said brakemeans are moved alternately into engagement with said sheet material,monitor means adapted to monitor the forward movement of said sheetmaterial through said apparatus and actuate said means adapted to rotatesaid rocker means upon the passage of a predetermined length of sheetmaterial past said monitor means to stop said sheet material,

sealing means adapted to contact said sheet material and effect a sealbetween the two layers of said sheet material and extending fully acrossthe width of said sheet material,

first cutter means disposed at a location rearwardly of and adjacent tosaid sealing means and adapted to sever said sheet material in a lineacross its width when said sheet material is stopped, said line ofseverance being substantially parallel to said seal, and

second cutter means disposed rearwardly of said first cutter means andadapted to cut an opening in the wall of said sheet material adjacentthe unsealed leading end of said sheet material.

2. The apparatus of claim 1 and including means adapted to maintain saidsheet material taut as it passes through said apparatus.

3. The apparatus of claim 1 wherein said drive roll means includes afriction drive roll means having a plurality of friction rings disposedabout its circumference at locations spaced along the length of saidroll.

4. The apparatus of claim 3 and including a further smooth surface driveroll means disposed in alignment with said friction drive roll means anddefining a nip therebetween.

5. The apparatus of claim 4 and including means connecting said frictiondrive roll means and said smooth surface drive roll means to one anotherfor simultaneous rotation thereof.

6. The apparatus of claim 1 wherein said brake means includes a brakeroll that is partially wrapped by said sheet material and an elongatedfriction means disposed in alignment with said brake roll and adaptedfor 1 4 movement between positions of engagement and disengagement withsaid sheet materialwrapping said brake roll.

7.'The apparatus of claim 1 and including piston-cylinder means havingthe piston member thereof connected to said rocker means for rotatingsaid rocker means upon extension and retraction of said piston member,and means adapted to activate said piston-cylinder means.

.8. The apparatus of claim 1 wherein said monitor means comprises ametering wheel frictionally engaging said sheet material as it movesthrough said apparatus, cam means rotatably connected to said meteringwheel, notch means in the periphery of said cam means, and switch meansincluding a switch arm engaging said cam means and adapted to activatesaid switch means when said switch arm enters said notch.

9. In an apparatus for the manufacture of an inflatable liner for adunnage bag employing a supply of bi layered sheet material of anindeterminate length that exceeds its transverse dimension theimprovement comprising in combination frame means, sheet material supplymeans connected to said frame means and adapted to store a supply ofsaid sheet material in position for dispensing said sheet material forforward movement through said apparatus,

first roll means disposed transverse to the forward di' rection of saidmaterial and adapted to receive said sheet material in partial wrappingengagement therewith,

friction means disposed in juxtaposition to said first roll means andadapted to move between positions of engagement and disengagement withsaid sheet material wrapped about said first roll means,

drive means adapted to progress said sheet material in its forwarddirection of movement, said drive means including friction drive rollmeans and a further drive roll, each disposed transverse to the forwarddirection of movement of said sheet material and defining a niptherebetween for frictionally receiving said sheet material therein andmeans mounting said friction roll means for movement between positionsof engagement and disengagement with said sheet material in said nip,means adapted to rotate said friction drive roll means whereby saidsheet material is moved forwardly through said nip when said frictionroll means is in its position of engagement with said sheet material,means monitoring the forward movement of said sheet material and adaptedtovp'rovide a signal upon the passage of a predetermined length of sheetmaterial past a preselected location on said apparatus, means connectingsaid means mounting said firction drive roll means to said frictionmeans, said connecting means adapted to move said friction means to itsposition of disengagement with said sheet material wrapped about saidfirst roll means and synchronously move said friction drive roll meansto its position of engagement with said sheet material when saidconnecting means is activated, sheet cutter means mounted on said framemeans and adapted to sever said sheet material transversely of itsdirection of forward movement upon actuation thereof, sealing meansdisposed at a location upstream from and adjacent to said cutter meansand extending transverse to the forward direction of said sheetmaterial,

means adapted to move said sealing means between a position ofengagement with said sheet material for effecting a seal between theoverlying layers fully across their width dimension, and a position ofdisengagement with said sheet material,

control means including means adapted to provide a first signal uponsaid sealing means engaging said sheet material and means adapted toprovide a second signal upon the completion of a seal across said sheetmaterial,

means adapted to receive said signal provided by said monitor means andin response thereto to activate said connecting means to move saidfriction means to its position of engagement with said sheet materialand to move said friction drive roll means to its position ofdisengagement with said sheet material to stop the forward movement ofsaid sheet material, and to receive said second signal provided by saidcontrol means and in response thereto to activate said connecting meansto move said friction means out of engagement with said sheet materialand to move said friction drive roll into engagement with said sheetmaterial to commence forward movement of said sheeet material,

further means adapted to receive said first signal provided by saidcontrol means and in response thereto to actuate said cutter means tosever said sheet material while said sheet material is stopped,

5 hole cutter means located between said sheet cutter means and saiddrive means and including suction means disposedd adjacent each of theopposite flat surfaces of said sheet material, the lower one of saidsuction means adapted to attract and hold the bottom layer of said sheetmaterial thereagainst upon the application of suction therethrough, theupper one of said suction means adapted to attract the top layer of saidsheet material thereagainst,

cutter means adapted to cut a plug from one of said layers while it isheld by said suction means and thereby provide an opening through saidlayer suitable for receipt of an inflation valve, and

means adapted to expel said plug from said cutter means at a locationremote from said sheet material, and

means adapted to apply suction to said suction means and means adaptedto activate said hole cutter means when said sheet material is stopped.

1. In an apparatus for the manufacture of an inflatable liner for adunnage bag employing a supply of flattened tubular sheet material ofindeterminate length that exceeds its transverse dimension theimprovement comprising in combination frame means, drive roll meansadapted to move said sheet material forwardly through said apparatus ina flat condition when in engagement with said sheet material, meansadapted to rotate said drive roll means, brake means adapted to stopmovement of said sheet material through said apparatus when inengagement with said sheet material, rocker means connecting said driveroll means and said brake means, means connected to said rocker meansand adapted to impart a rotating motion to said rocker means wherebysaid drive roll means and said brake means are moved alternately intoengagement with said sheet material, monitor means adapted to monitorthe forward movement of said sheet material through said apparatus andactuate said means adapted to rotate said rocker means upon the passageof a predetermined length of sheet material past said monitor means tostop said sheet material, sealing means adapted to contact said sheetmaterial and effect a seal between the two layers of said sheet materialand extending fully across the width of said sheet material, firstcutter means disposed at a location rearwardly of and adjacent to saidsealing means and adapted to sever said sheet material in a line acrossits width when said sheet material is stopped, said line of severancebeing substantially parallel to said seal, and second cutter meansdisposed rearwardly of said first cutter means and adapted to cut anopening in the wall of said sheet material adjacent the unsealed leadingend of said sheet material.
 2. The apparatus of claim 1 and includingmeans adapted to maintain said sheet material taut as it passes throughsaid apparatus.
 3. The apparatus of claim 1 wherein said drive rollmeans includes a friction drive roll means having a plurality offriction rings disposed about its circumference at locations spacedalong the length of said roll.
 4. The apparatus of claim 3 and includinga further smooth surface drive roll means disposed in alignment withsaid friction drive roll means and defining a nip therebetween.
 5. Theapparatus of claim 4 and including means connecting said friction driveroll means and said smooth surface drive roll means to one another forsimultaneous rotation thereof.
 6. The apparatus of claim 1 wherein saidbrake means includes a brake roll that is partially wrapped by saidsheet material and an elongated friction means disposed in alignmentwith said brake roll and adapted for movement between positions ofengagement and disengagement with said sheet material wrapping saidbrake roll.
 7. The apparatus of claim 1 and including piston-cylindermeans having the piston member thereof connected to said rocker meansfor rotating said rocker means upon extension and retraction of saidpiston member, and means adapted to activate said piston-cylinder means.8. The apparatus of claim 1 wherein said monitor means comprises ametering wheel frictionally engaging said sheet material as it movesthrough said apparatus, cam means rotatably connected to said meteringwheel, notch means in the periphery of said cam means, and switch meansincluding a switch arm engaging said cam means and adapted to activatesaid switch means when said switch arm enters said notch.
 9. In anapparatus for the manufacture of an inflatable liner for a dunnage bagemploying a supply of bilayered sheet material of an indeterminatelength that exceeds its transverse dimension the improvement comprisingin combination frame means, sheet material supply means connected tosaid frame means and adapted to store a supply of said sheet material inposition for dispensing said sheet material for forward movemEnt throughsaid apparatus, first roll means disposed transverse to the forwarddirection of said material and adapted to receive said sheet material inpartial wrapping engagement therewith, friction means disposed injuxtaposition to said first roll means and adapted to move betweenpositions of engagement and disengagement with said sheet materialwrapped about said first roll means, drive means adapted to progresssaid sheet material in its forward direction of movement, said drivemeans including friction drive roll means and a further drive roll, eachdisposed transverse to the forward direction of movement of said sheetmaterial and defining a nip therebetween for frictionally receiving saidsheet material therein and means mounting said friction roll means formovement between positions of engagement and disengagement with saidsheet material in said nip, means adapted to rotate said friction driveroll means whereby said sheet material is moved forwardly through saidnip when said friction roll means is in its position of engagement withsaid sheet material, means monitoring the forward movement of said sheetmaterial and adapted to provide a signal upon the passage of apredetermined length of sheet material past a preselected location onsaid apparatus, means connecting said means mounting said firction driveroll means to said friction means, said connecting means adapted to movesaid friction means to its position of disengagement with said sheetmaterial wrapped about said first roll means and synchronously move saidfriction drive roll means to its position of engagement with said sheetmaterial when said connecting means is activated, sheet cutter meansmounted on said frame means and adapted to sever said sheet materialtransversely of its direction of forward movement upon actuationthereof, sealing means disposed at a location upstream from and adjacentto said cutter means and extending transverse to the forward directionof said sheet material, means adapted to move said sealing means betweena position of engagement with said sheet material for effecting a sealbetween the overlying layers fully across their width dimension, and aposition of disengagement with said sheet material, control meansincluding means adapted to provide a first signal upon said sealingmeans engaging said sheet material and means adapted to provide a secondsignal upon the completion of a seal across said sheet material, meansadapted to receive said signal provided by said monitor means and inresponse thereto to activate said connecting means to move said frictionmeans to its position of engagement with said sheet material and to movesaid friction drive roll means to its position of disengagement withsaid sheet material to stop the forward movement of said sheet material,and to receive said second signal provided by said control means and inresponse thereto to activate said connecting means to move said frictionmeans out of engagement with said sheet material and to move saidfriction drive roll into engagement with said sheet material to commenceforward movement of said sheeet material, further means adapted toreceive said first signal provided by said control means and in responsethereto to actuate said cutter means to sever said sheet material whilesaid sheet material is stopped, hole cutter means located between saidsheet cutter means and said drive means and including suction meansdisposedd adjacent each of the opposite flat surfaces of said sheetmaterial, the lower one of said suction means adapted to attract andhold the bottom layer of said sheet material thereagainst upon theapplication of suction therethrough, the upper one of said suction meansadapted to attract the top layer of said sheet material thereagainst,cutter means adapted to cut a plug from one of said layers while it isheld by said suction means and thereby provide an opening through saidlaYer suitable for receipt of an inflation valve, and means adapted toexpel said plug from said cutter means at a location remote from saidsheet material, and means adapted to apply suction to said suction meansand means adapted to activate said hole cutter means when said sheetmaterial is stopped.